Reciprocating motor and interrupting switch



P 1933. A. D. ALTEMILLER 1,925,360

RECIPROCATING MOTOR AND INTERRUPTING SWITCH Filed Oct. 10, 1932 EH 1 Fa L. 3 1' -E- IIZZI'ILLZ'IIIZ' Q Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE RECIPROCATING MOTOR AND INTER- RUPTING SWITCH Application October 10, 1932. Serial No. 636,979

3 Claims.

This invention relates to a reciprocating motor in combination with an interrupting switch.

An object of this invention is to provide a reciprocating motor operable by thermal contraction of a resistance wire in a circuit with means for interrupting the flow of electric current through said resistance wire and to provide circuit connections whereby the means for interrupting the current through the resistance wire may also serve as a switch for the circuit.

Other and specific objects will be apparent from the following detail description taken in connection with the accompanying drawing, in which Fig. 1 is a side elevation with one of the cover plates in section taken substantially on line 1-1,

Fig.2.

Fig. 2 is a front elevation.

Fig. 3 is a rear elevation.

Fig. 4-is a detail sectional view on line ipi, Fig. l.

The device includes plates 1 and 2 which provide a frame or support for the device. A cradle 3 is pivoted on a pin 4 supported by the plates 1 and 2 and carries a mercury tube switch 5 at its upper end. The mercury switch 5 is of conventional construction and includes a pair of terminals 6 positioned in one end of a sealed tube 7, which encloses a globule of mercury 8. The operation of such a switch is well understood in the art. Its construction is such that the position of the tube will the mercury to flow toward one of the two ends of the tube, that is either toward the contacts 6 and thus connect them or toward the opposite end leaving the pair of contacts 6 separated from each other.

Stop pins 9 and 10 are provided to limit the movement of the cradle 3. Thus, when the cradle 3 is in the position shown in Fig. 1, that is against the stop 10, the mercury switch 5 will be in on position, but when the cradle 3 is rocked about its pivot 4 to a position in which it abuts the stop 9 the mercury globule 8 will be positioned away from the terminals 6 and the circuit will be open.

Lead wires 11 and 12 form a part of the circuit to be opened and closed. For convenience these wires are secured to binding posts 13 and 14, re-

spectively. The wire 11 is connected to one of the terminals 6 and the wire 12 is electrically 50 connected, by means which will later be described, to a wire 15 which is connected to the other terminal 6 of the mercury switch 5.

The cradle 3 is moved on its pivot 4 by a spring 16 having one end connected to a pin 1'7 on the g cradle 3 and its other end connected to the long arm of a lever 18, pivoted on a pin 19, which is secured between the plates 1 and 2. The cradle 3 is moved by the spring 16 which will tend to move the cradle counter-clockwise (Fig. 1) when the spring lies above the pivot pin 4, and to move the cradle clockwise when the spring lies below the pin. A weight 20 is supported at the end of an 21, which is by a set screw 22 to a shaft 23, journalled in the plates 1 and 2. An arm 24 is securely fastened to the shaft 23, as by welding. A link 25 is connected to the outer end of the arm 24 by a pivot pin 26 and is connected to the outer end of the lever 18 by a pivot pin 27. It will thus be seen that the weight 20 is effective to move the lever 18 in one direction; that is, the downward movement of the weight 20 moves the long arm of the lever 18 in an upward direction.

A thermal element is provided to move the lever 18 in opposition to the weight 20. This thermal element comprises a plurality of loops of resistance wire 28 connected between the wires 12 and 15 and wound between a spool 29, fixed between the plates 1 and 2, and a spool 30. The spool 30 is secured to a link 31 pivotally connected to the lever 18 by a pin 32.

One end of the resistance wire 28 is secured to the spool 29 and the opposite end is secured to the spool 30. An electrically non-conductive guide member 33 having grooves 34 is, for convenience, positioned between the spools 29 and 30, the grooves 34. being arranged to receive the loops of the wire 28. It will be understood that the spools 29 and 30 are constructed of electrically non-conductive material.

The wire 28 has r latively high ohmic resistance and preferably has a high co-efiicient of lineal expansion whereby it will become heated and materially lengthen when current is passed through it. The result of such heating is to permit the weight 20 to rock the lever 18 to a position in which the cradle 8 is pulled against the stop 9 by the spring 16 and the switch 5 opens the circuit. The wire 28 thereupon cools and contracts, thereby rocking the lever 18 against the weight 20 and causes the cradle 3 to rock to a position against the stop 10 thereby closing the circuit. This action will continue as long as the wires 11 and 12 are connected to a source of current supply.

The action of the device is such as to cause the shaft 19 to rock. A mechanical connection such as a bell crank lever may be attached to the shaft 19 and the device will thereby serve as a reciprocating motor. Thus, the device is adapted for use in connection with a display sign since the rock shaft 19 may be mechanically connected to impart a reciprocating motion to any part of the sign which is required to be moved and the switch may be utilized for controlling the flow of electric current to illuminating devices on the sign. It will be understood, of course, that the device is not limited to such use and may be employed to advantage for many uses where a reciprocating motor is desired, or where an interrupting switch is desired, or where a device capable of both functions is required.

The resistance wire 28 in the specific embodiment shown in the drawing is illustrated as connected in series in the circuit but it will be understood that this wire may also be connected in parallel. Parts of the invention may be used without the whole and other details of construction may be varied, within the scope of the appended claims, without departing from the spirit of this invention.

I claim:

1. Means for operating an electric switch including a fixed spool, a movable spool, a plurality of loops of resistance wire wound between said spools and having one end secured with respect to the fixed spool and the other end secured with respect to the movable spool, means connecting said wire in said circuit, a lever adapted to operate the switch, and mechanical conections between the movable spool and the lever whereby movement of said spool will operate the lever.

2. Means for operating a switch for an electric circuit including a lever for operating the switch, a second lever, a spring connected between said levers and adapted to move said first lever upon a sufiicient movement of the second lever, a fixed support, a resistance wire secured between the fixed support and the second lever whereby contraction of the wire will move the lever, said wire being connected in said circuit and adapted to be heated by current therethrough, and means for yieldingly holding said second lever against tension by the contraction of said wire.

3. Means for operating an electric switch including a fixed spool, a movable spool, a plu rality of loops of resistance wire wound between said spools and having one end secured with respect to the fixed spool and the other end se cured with respect to the movable spool, an elon gated non-conductive member extending between the spools and having a plurality of grooves each positioned and adapted to receive a strand of the wire, and a mechanical connection between the movable spool and the switch whereby contraction of the wire places the switch in on position.

ARTHUR D. ALTEMILLER. 

